Ethical worries have slowed medical research into applications for stem cells. But scientists like Robert Lanza have developed less controversial ways to derive stem cells from normal body cells rather than embryos and are already launching the first clinical trials.

Stem cell researcher Robert Lanza hopes to save thousands of lives — and for a long time this caused him to fear for his own.

‘They bused these crazy people up from Kansas, and then they picnicked right outside our front door,’ he says as he gazes out of his window at the gray winter landscape of Marlborough, Massachusetts. ‘The public thought we had these little buggy-eyed embryos here and were ripping apart their limbs to get these cells.’

The physician always feared ‘somebody hiding in the bushes,’ waiting to attack him. At the time, a doctor was threatened at a nearby fertility clinic, and a pipe bomb exploded at a bio lab in Boston.

‘Back then I thought that there was probably a 50-50 chance that I was going to get knocked off because I was so visible,’ says the doctor. Then he leans back in his chair and laughs. Lanza likes to flirt with danger: ‘I said, okay, try to kill me […]